The invention relates to the field of components with optical fibers and associated optical fibers. The invention in particular relates to the field of components with optical fibers and associated optical fibers, when the optical fibers are at least partly bent with small radii of curvature on the one hand and on the other hard intended for conveying significant optical energy. The optical fiber is bent with a small radius of curvature, notably at the output connection or else when the casing into which it is inserted, is that of a miniaturized component. In this type of component, the optical losses at the optical fiber level are significant.
U.S. Pat. No. 6,373,868 relates to a method for configuring a standing-wave cavity arrangement for solid-state lasers in obtaining stable single-mode operation, whereby overcoming the major difficulty, with intracavity frequency conversions, typically in frequency doubling caused by the so-called “green problem”.
GB 2,313,330 relates to an optical fiber for use in carrying out spectral analysis, wherein the fiber is provided with a protective coating which is formed from a material which is substantially non-absorbent to radiation in the infra-red range.
US 2003/0133679 relates to an optical fiber comprising a flame retardant UV light-curable tight-buffer coating, which is substantially halogen-free and has a limiting oxygen index of at least 20%, and wherein the tight-buffer coating has an optical transparency of at least 75% at a wavelength of 400-800 μm.
EP 0 475 369 relates to an apparatus for measuring and controlling the eccentricity of the colored coating layer of optical fibers, wherein the measurement is made by analyzing the interference patterns obtained by launching onto the fiber two monochromatic light beams which are perpendicular to each other and to the optical fiber axis. The pigmented polymers have the characteristic of being practically transparent in the portion of the optical spectrum ranging from 850 nm to 2500 nm″ belonging to the near infra-red.
According to the prior art, for an optical fiber, conveying a significant optical energy while being bent with a small radius curvature, is a matter for a compromise impossible to achieve. Indeed, either the radius of curvature of the bent optical fiber is small and then the optical energy to be conveyed by the optical fiber must then be limited, or the optical energy to be conveyed by the optical fiber is high and then the reduction of the radius of curvature of the bent optical fiber must be limited, i.e. the miniaturization of the component must be limited. The problem of increasing the optical energy to be conveyed in the optical fiber while reducing the radius of curvature of the bent optical fiber lies in the fact that the energy absorbed in the coating of the optical fiber is thereby increased a great deal, which coating not withstanding a very high internal temperature, is then degraded rapidly.
Examples of such coatings are notably:                UV-polymerized coatings based on urethane-acrylate;        coatings based on siliconized polymer such as those described in U.S. Pat. No. 6,652,975 or in Patent Abstract of Japan JP 53131851 which are polymerized by heat and not by ultraviolet radiation;        multilayer coatings based on siliconized polymer on the one hand and on siliconized polyimide on the other hand, such as those described in U.S. Pat. No. 4,848,869 which are polymerized by heat and not by ultraviolet radiation.        
Patent Abstract of Japan JP 61186906 describes a coating based on siliconized polymer for a plastic optical fiber, the optical core of which is not based on silica.
Patent Application US 2003/0,199,603 describes an optical fiber coating which is transparent to ultraviolet radiation.